Furnace grate



Feb. 23 1926. v

A. w. BENNES FURNACE GRATB 3 Sheets-Sheet 1 Filed May 6, 1919 Feb. 23 1926.

A. W. BENNIS FURNACE GRATE Filed May 6, 1919 3 Sheets-$heet 2 Feb. 23 1926. r 1,574,276

r v A. w. BENNIS FURNACE cant May 6 1 9 Patented Feb. 23,

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ALFRED WILLIAM BENNIS, OLE BOLTON, ENG-LAND.

FURNACE ennrn;

Application filed May 6,

To all whom it may concern.

Be it known that T, ALFRED, WIL IAM BEN- N15, a subject of the King of Great Britain, residing at Bolton, in the county of Lancasterand Kingdom of England, have invented certain new and useful Improvements in Furnace Grates, of which the following is a specification. v

The present invention relates, to improvements in furnace grates and more particularly to those types of furnace grates known astravelling chain grates and step grates, and its object is to improve the same in varions particulars and combine the advantages of each type whilst eliminating the disadvantages peculiar to each such type used as at present constructed.

It has for one of its objects to provide a better and more efiicient design and arrangement than has hitherto existed of the links, fire bars, or the like of travelling chain grates or of similar parts in step grates by which, aside from other advantages and in addition to such fuels as are commonly burned, it will be possible to eificientlyburn fuels'that are low in calorific value, either fine or otherwise in size, such as have hitherto been largely wasted, and for this and other objects my invention provides a better and more efficient proportioning and disposition of the air spaces in their relation to the links, fire bars or the like than has heretofore been employed in travelling chain grates or in grates of the step type.

My invention also has for one of its objects to achieve the automatic cleaning or clearing out of the air spaces or some of them by the relative motion of the links, fire bars or the like, one to another, when turning about the drums, sprockets or the like at the ends of the travelling chain grate; and furthermore, by the employment of novel features of design, my invention will substantially prevent any loss by riddling or falling through the travelling chain grate of the material that is being burned or carried thereon.

The grate of .the present invention consists of fire bars each having a centre portion preferably substantially horizontal when in operation, a front lip portion which may be higher than said centre portion and a rear lip portion lower than said centre portion, the under surface of the rear lip portion being concave.

l/Vhen such firebars are linked together 3.919. SerialNo. 295,208.

to form a chain grate the rear lip portion of front lip portion of the next fire bar behind which might otherwise tend to choke the air space formed between the various steps or surfaces.

The concave part or under surface of the front lip portion may be cylindrical having as axis the pivotal axis of the fire bar in front. V j

. The invention is more particularly described with reference to the accompanying drawings, in which:

Figure 1 is a diagrammatic side View, partly in section, of an inclined grateaccording to this invention, showing chambers and accessories foruse. 7

Figure 2 is a diagrammatic View, showing two bars connected to form a portion of a grate.

Figure 3 is a corresponding plan view.

'igure 1 is a sectional side elevation,

showing a plurality offire bars of a modified form of construction connected to form a portion of grate. V

Figure 5 is a view partly in section on the line 55 of Figure 4: with some of the fire bars removed.

The travelling grate may be either horizontal or, as shown in Figure 1, the upper run 1 of the grate may be inclined to'the horizontal, while the bottom run 2 maybe parallel thereto as shown.

A fuel feed hopper 8 is provided having a cut off 1 by which the passage of fuel to the grate surface is controlled.

The grate comprises a plurality of fire bars 5, linked end to end and passing over a front drum or sprocket 6 and a rear drum '2', any suitable continuous or intermittent driving means being provided therefor.

The chain grate thus assembled is mounted on a frame 10, having the usual adjuncts 60 it and so clear outany accumulation of ashes overlapped at one edge by a corresponding part on the next fire bar, mounted on a link 19 having hinge pivots 19 and 19 If this fire bar be carefully examined, it will be noticed that the important and novel feature of this invention namely, the sweep ing through of the air space 19 by the toe part 19 of the fuel supporting surface 19 as the chain moving in the direction of the arrow 31 passes over the rear drum- 7, is secured by arranging that the pivot 19 firstly lies outside the projection of the fuel supporting surface 19 onto the plane of the pivot axes 19 and 19 and secondly, 111 a direction away from the intersection line 19 .of the plane of the part 19 and the plane of the pivot axes 19 and 19, which latter is usually of course, also the line of motion of the grate.

This sweeping-through motion permits the main air supply feed channels 19 to the grate to remain clear of clinker, or the like rubbish otherwise apt to accumulate.

Another type of fire bar is that shown in reference to Figures 3 and at in which a plu rality of narrow fire bars 20 are connected side by side and are pivotally connected end to end by means of rods 21 connecting them also to the driving chains 22. These narrow fire bars have each a centre surface 23, a front lip portion 24 and a rear lip 25, the grate travelling in the direction of the arrow 26. The rear lip 25 as the grate passes over the sprocket 27 sweeps through the cutaway space 28 under the front lip portion 24; and so maintains this air space clear of any accumulation of ashes. This air space can be extended by means of a rib 29, which, when the grate is intermediate the front and rear sprockets will form an extension of the fuel supporting surface 23, 25, of the fire bars and will be continuous to the rear lip 25, thus forming an air channel 30 leading air up through the space between the under surface of the front lip portion 24 and the rear lip 25. y r

The top of the front lip 24 and the top of the rear lip 25 are shown as parallel to one another, but this, whilst it is desirable, is'not absolutely essential.

A sprocket ordrum 27 is provided with teeth 27 adapted to engage with the rods 21 between connections of adjacent fire bars as shown in Figure 4.

Y What I claim and desire to secure by Letters Patents is 1. A'chain grate fire bar having an inclined fuel supporting surface and a pair of pivotal axes, one of said axes lying outside the projection of the saidfuel supporting surface on the plane containing said axes, and on the side of the fuel supporting surface opposite the intersection of the plane of the fuel supporting surface and the plane containing the said axes.

2. A chain grate comprising a plurality of fire bars each having an inclined fuel supporting surface and a pair of pivotal axes, one of said axes lying outside the pro jection of the said fuel supporting surface on the plane containing said axes and on the side of the fuel supporting surface opposite the intersection of the plane of the fuel supporting surface and the plane containing the said axes, and means to connect the pivotal axes of said fire bars to form an endless grate.

3. A chain grate comprising a plurality of fire bars each having an inclined fuel supporting surface and a pair of pivotal axes, one of said axes lying outside the projection of the said fuel supporting surface on the plane containing said axes and on the side of the fuel supporting surface opposite the intersection of the plane of the fuel supporting surface and the plane containing the said axes, a driving chain, and means to connect said pivotal axes to said driving chain.

4. A chain grate comprising a plurality of fire bars of greater length than width, each having a fuel supporting surface, and a pair of pivotal axes, one of'said axes lying outside the projections of the said fuel supporting surface on the plane containing said axes and on the side of the fuel supporting surface opposite the intersection of the plane of the fuel supporting surface and the plane containing the said axes, a driving chain, and means to connect said pivotal axes to said driving chain.

5. A chain grate comprising a plurality of fire bars each having an inclined fuel supporting surface and a pair of pivotal axes, one of said axes lying outside the projection of the said fuel supporting surface on the plane containing said axes and on the side of the fuelsupporting surface opposite the intersection of the plane of the fuel supporting surface and the plane containing the said axes, means to connect the said pivotal axes to said fire bars to form an endless grate and ribs on said bars forming extensions of air passages on one bar to its next adjacent bar.

In witness whereof, I have hereunto signed my name this 29th day of March 1919.

ALFRED WILLIAM BENNIS. 

